Supervee 27 Question

[philly123]

So, I am pretty new to the boat scene and have a few questions. Ive been into the rc hobby for over 10 years so I have knowledge of how to build the boat just not how to make it handle properly. The hull I am currently having some trouble with is the Supervee 27. I will post pics to make it easier to see the set up.

The main problem is that once I start to pick up speed the boat wobbles from side to side and also it seems as if the front wants to lift. I moved the batteries forward a little and tried messing with the trib tabs. Is there anyway to adjust the trim tabs other than eyeballing it?

[PowerDemon]

What you have from what it sounds like is chine walk. You would solve this by putting your trim tabs down about 1mm at a time and your strut 1mm at a time until your boat stops doing this. Also move your batts forward as far as they will go. It could also be purposing which would be the bow bouncing up and down and you would solve that the same way you would fix chine walk by moving your batts forward your strut and tabs until it stops. The way I measure tabs is by putting a straight edge under the hull and line it up with the tab. I usually just eyeball it or count the turns on the wrench as I put them down. Good luck with the new boat and hope this helps!

[philly123]

Ok thanks ill give it a shot next time out

[philly123]

20140615_155334.jpg20140615_155125.jpg
Here is the setup.

[PowerDemon]

That is a really nice setup! It appears that all the hardware on the hull is highly adjustable so you can change the boats riding attitude to your liking. Let us know how your next run goes! Good luck!

[siberianhusky]

You are pretty much describing how an SV runs at speed, they are limited in top speed by the hull design. Don't forget the nickname for this boat - The Super Flip.
I run mine with a UL-1 motor, weighed the difference between lipo and NiMh packs, added the difference in weight in lead right at the CG.
Doesn't eliminate the problems completely but it did help a lot.
If you wanted to to a complete rebuild I'd change the stinger out for a strut and RAISE it up a bit to get the hull deeper in the water, lowering it will raise the hull out of the water making the chine walk WORSE! I'm not talking angle here I'm talking raise the entire driveline and still run a neutral strut setting.
Gotta remember this boat was originally designed to run a 1500kv motor with a pair of NiMh packs in series.
I love my SV, the most fun we have is when everybody brings out the old SV's and we get 4 or 5 on course, fun racing! Also the boat I never seem to have any problems with, still running the old non lipo esc with the UL-1 motor. Can't kill that thing!

[philly123]

I moved the batteries forward and lowered the trim tabs and the stinger. Just havent had a chance to test it yet. How would changing to a strut help?

Luckily I have only had one blow over since i built the new set up and it survived lol.

[siberianhusky]

Because with the proper setup you can actually raise or lower the strut, with the stock SV setup all you can do is change the angle. By running negative on the strut and dialing down trim tabs you are not getting the same kind of adjustment as raising the strut.
You are basically forcing the nose down as opposed to letting the running surfaces of the hull ride lower in the water.
There is a lot of lift in the sv hull design, this causes the hull to ride on a small V section at the stern, by letting the hull run a bit deeper more of the V is in the water dampening out the chine walk or side to side rocking.
All goes back to the hull design, the SV was designed with a lower kv motor and heavier batteries in mind, run more rpm and lighter batteries and it rises out of the water too far.
As I said I added weight to mine, still can get a bit of chine walk at the end of the straight at top speed but nowhere near as bad as it was. Also runs better in the turns with the stinger and trim tabs neutral, bottom of the rudder tilted forwards as far as the stock adjustment will allow. This is counter intuitive to your changes in regards to the turns, the rudder will be trying to plant the transom the tabs and negative in the stinger will be trying to raise it and plant the nose......
It's all a balancing act, for me the lap time in more important than overall top speed, having a boat that is a rocket on the straights but turns like a pig on skates is useless to me as half the lap is turns!
With all the changes you made at once how do you know which one works? Should only make one change at a time and run the boat. Don't go for a full length run - run for a minute or less bring it in and check the temps. If it's running wet it will be an amp hog and you may overheat something.
There is a lot more to having a fast boat than a motor and prop! Gotta learn how to properly tune it.

[philly123]

Thanks for your help. I dont know if i want to change to a strut just yet. But which one would you recommend for such a small boat?

[siberianhusky]

Anything that has the same stand off length as the stinger. Hobbyking has a few inexpensive struts shat should work on a SV if you decided to change.
You don't want to change the distance the prop is from the transom. It is kind of tied to boat length and how far back the rudder is, which you don't need to change.

[philly123]

I am finally going to get out on the lake this Saturday to test the changes.

Also, I have been seeing that people are using a BEC with electric boats. What are they exactly and what do they do?